In administration of power systems, plan drafts for maintaining supply reliability are important. Even in a case in which defects occur in equipment of the power systems, it is necessary to maintain operations of the power systems and continue power supply. The power system is one of the important social infrastructures. To maintain supply reliability in the power system is one of the duties of power system administrators.
The basic ideas for maintaining the reliability is a preventive plan draft by preliminary analysis. Supply trouble causes which can occur in power systems are assumed preliminarily, and then it is determined whether states in which the supply trouble causes occur can be evaluated in terms of analysis calculation and whether power supply can be continued. Power system administration plans are drafted under the condition that there is no problem even when any of the assumed supply trouble causes occurs.
As an example of the power system administration technologies, stability maintenance control can be exemplified. For example, as in PTL 1 and PTL 2, drafts of optimum stability maintenance countermeasures by collecting measurement information regarding power systems online have been proposed. In this way, advances in calculator technologies and communication technologies improve the reliability of power systems.